1. Field of the Invention
The present invention relates to a digital broadcast service and, in particular, to a Right Object renewal method capable of predicting the expiration of, and renewing, a Right Object prior to the predicated expiration of the Right Object.
2. Description of the Related Art
A digital broadcast receiver enables tuning to frequencies carrying digital broadcast signals. Typically, the digital broadcast signals are digitally encoded and modulated, and thus the broadcast receiver must demodulate and decode the received broadcast signals to present the received signals to a user or other type of equipment (e.g., a display system). In order to receive and process the received digital broadcast signals, a digital broadcast receiver includes a tuner, a broadcast data demodulator, and a broadcast data decoder. Recent digital broadcast systems are classified into a digital multimedia broadcast (DMB) system and a digital video broadcasting (DVB) system. These digital broadcast systems provide a plurality of service channels in a given frequency bandwidth, and each service channel carries broadcast program data and program information.
In case of DVB-Handheld (DVB-H) system, a service channel is multiplexed with audio/video data and supplementary program information. The audio/video data are transported using the Real Time Transport (RTP) protocol, and the program information is transported using the FLUTE protocol. The FLUTE protocol is built on top of the Asynchronous Layered Coding (ALC) protocol including a Layered Coding Transport (LCT) protocol. The FLUTE packets carry a File Delivery Table (FDT) and Object Data.
The DVB-H digital broadcast receiver can also be configured to support a Digital Right Management (DRM) for billing to a specific broadcast channel. In this case, the broadcast of the channel is provided to the subscribers having the right to use specific data content. The DRM can be implemented using various well-known right restriction methods, e.g. duration restriction and playback number restriction. With the widespread use of the mobile terminals and expectation of an increase of the broadcast-enabled mobile terminals, there is a need to develop a right protection method appropriate for the DVB-H service and efficiently managing the license issued for the right-protected broadcast channel.